I think this is where Deepseek has nailed the mark; DS4.1 Flash is really, really fast, and really, really cheap. If you give it small, structured goals, it completes them crazy quick, at negligible cost. There's different vectors to differentiate along to stay in the conversation.

I've taken to using them as micro-review subagents at development milestones, where a "frontier - 1" model like Opus or Sol launches 10-15 of them on small review tasks that each run for ~10 minutes. Costs about $1 per cycle, and they usually catch something Astra or Fable didn't. Then the orchestrator validates each claim before passing it back to the planning session so we can fold the findings in.